Electrostimulation therapies come in a variety of flavors including cranial electrostimulation therapy (CES). Other common electrostimulation therapies include transcranial magnetic stimulation (repetitive TMS, or rTMS) therapy and electroconvulsive therapy (ECT). Cranial electrostimulation therapy is the mildest of the bunch. But the question is, does CES work? What is the evidence, or lack thereof, for CES in those with major depression or bipolar depression?
I’ll start out by stating my bias. I don’t believe in an at-home electrostimulation device for major depression. I don’t believe in such a device made by several misleading manufacturers. And I especially don’t believe in a device wherein a 2014 Cochrane review of it found zero “methodologically rigorous studies of CES in treatment of acute depression.”
So you can color me skeptical, at best. Nevertheless, when I did this review, I was prepared to be proven wrong.
Cranial Electrostimulation Devices
Cranial electrostimulation (CES, or transcranial alternating current stimulation [tACS]) devices use a very small, alternating current to stimulate regions of the brain. There are several possible electrode placements and settings. These devices are available for sale with a doctor’s prescription. They cost around $600-$800 and, typically, very little of this is reimbursed by insurance when it is used to treat major depression or bipolar depression. There are very few side effects reported by those who use CES devices.
The use of the term “alternating” in the above is very important as transcranial direct current stimulation (tDCS) also exists. The two types of stimulation are delivered by separate devices and have separate evidence bases. At this time, tDCS devices are not approved for use by the Food and Drug Administration in the United States and are not discussed below.
Cranial Electrostimulation (CES) Devices for Depression
Fisher Wallace, a main manufacturer of CES devices, lists 13 studies/reviews on the effects of CES on depression and anxiety (the conditions are grouped together on their site). That said, exactly none of those looks at the effect of CES on depression alone (i.e., not with comorbid disorders) in the last 10 years and one (a study) looks at the effect of CES on bipolar depression. (One additional study from 1972, one from 1997 and one from 2005 are also listed.)
Not surprisingly, the Cochrane review mentioned above is not listed.
Evidence for CES Devices for People with Major Depression
As there is no listed evidence for CES devices helping major depression in the last 10 years, let’s go back 11 for “A Monograph” written by Ray B. Smith Ph.D.
This single review for cranial electrostimulation devices for depression in the last 11 years looked at 18 studies, altogether containing 853 patients. That sounds like a lot. However, of the 18 studies only two were double-blind and looked at patients with depression alone (and not with some other comorbid condition such as substance abuse or fibromyalgia). When you add up how many people were in those studies you get 29. And these 29 people were treated in 1973 and 1975. Again, it’s impossible to generalize how the millions of people with major depression would fare based on a whole 29 people.
I would ask, if this device was so profoundly efficacious, wouldn’t a double-blind, randomized, placebo-controlled study have been run in the intervening 42 years? I would think so.
Additionally this small study of 30 patients (more than the above, notably) with treatment-resistant major depressive disorder shows that CES was no more useful than sham treatment.
Evidence for CES Devices for People with Bipolar Depression
The study on bipolar depression currently appears at the top of the Fisher Wallace Stimulator Scientific Evidence page. It has a nice graph and everything.
But here’s the thing: it’s a single study of 16 people. I cannot and will not generalize about how well a device might work for a population of millions in the United States based on the seven people* who actually received it for two weeks, no matter how pretty the graph. Of course, the authors of the study also note that it is only a “pilot study.” Seven people aren’t worth a conclusion of efficacy, that’s for sure. My guess is the manufacturer is really hoping you’ll look at the graph and not actually look at the study.
* The seven people actually increases to all 16 for two weeks of open-label treatment after the two weeks of blinded treatment.
Evidence for Cranial Electrostimulation Therapy (CES) in Treating Depression
In short, there is little-to-no high-quality evidence that cranial electrostimulation (CES) therapy works for those with depression. (It may work for other conditions, I don’t know, I did not do a thorough review of those cases.)
I’d hate to say that the manufacturers of these devices are preying on those with mental illness and trying to sell them something they can’t afford with little evidence of usefulness, but one might come to that conclusion. The people I know with serious major depressive disorder certainly couldn’t afford such a device and if they bought one, it would be a great hardship.
For that reason, I think it’s important to understand the evidence base or lack thereof. All I can say of this device is caveat emptor – buyer beware.
Kavirajan, L. C. (2014). Alternating Current Cranial Electrotherapy Stimulation (CES) for Depression. The Cochrane Database of Systemic Reviews. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/25000907
McClure, G. K. (2015). A Pilot Study of Safety and Efficacy of Cranial Electrotherapy. The Journal of Nervous and Mental Disease, 827–835. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4892785/
Mischoulon, D. J. (2015). Efficacy and Safety of a Form of cranial Electrical Stimulation (CES) As an Add-On Intervention for Treatment-Resistant Major Depressive Disorder: A Three Week Double Blind Pilot Study. Journal of Psychiatric Research, 98-105. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/26424428
Smith. (2006). Cranial Electrotherapy Stimulation: Its First Fifty Years, Plus Three. Washington D.C. Retrieved from http://cdn.shopify.com/s/files/1/0315/7737/files/Cranial_Electrotherapy_Stimulation.pdf?315
Xenakis, M. (2014, July 24). The Rise of Cranial Electrotherapy. Retrieved from Psychiatric Times: http://www.psychiatrictimes.com/electroconvulsive-therapy/rise-cranial-electrotherapy